Space diversity method

ABSTRACT

A space diversity method is disclosed having the steps of: setting space-frequency block coder (SFBC) based on Alamouti coder as the minimum unit of space-time coder; orthogonally processing the SFBC to acquire the transmission signals of part of antenna ports in eight antenna ports, and cyclically delaying the acquired transmission signals of antenna ports to obtain the transmission signals of the rest antenna ports; transmitting the acquired transmission signal in the corresponding time and sub-carrier by each antenna port. A space diversity device is also provided which has an orthogonal processing module, a signal cyclic delay module and a transmitting module. With the method and device, the eight-antenna data transmission in the long time evolution (LTE) advanced system is achieved, and better diversity gain is acquired without adding extra pilot overhead.

TECHNICAL FIELD

The present invention relates to the diversity technology in the longterm evolution (LTE) Advanced system, and more especially, to a spacediversity method and device based on cyclic delay in the LTE Advancedsystem.

BACKGROUND OF THE RELATED ART

In the long term evolution (LTE) system, diversity methods for the casesthat there are two transmission antennae and that there are fourantennae are defined in the downlink, wherein, the diversity method forthe case that there are two transmission antennae is space-frequencyblock coder (SFBC), whose coder matrix is shown in equation (1):

$\begin{matrix}{\mspace{85mu} {{{Antenna}\; 1\mspace{14mu} {Antenna}\mspace{11mu} 2}{\begin{matrix}\underset{1}{Frequency} \\\underset{2}{Frequency}\end{matrix}\begin{bmatrix}S_{1} & {- S_{2}^{*}} \\S_{2} & S_{1}^{*}\end{bmatrix}}}} & (1)\end{matrix}$

In equation (1), each column indicates one transmission antenna and eachrow indicates one transmission frequency; S₁ indicates the symbol sentin the first time, S₂ is the symbol sent in the second time, S₁* and S₂*indicate the conjugates of S₁ and S₂ respectively.

The diversity method for the case that there are four transmissionantennae is space-frequency block coder (SFBC)+frequency switch transmitdiversity (FSTD), whose coder matrix is shown in equation (2):

$\begin{matrix}{\mspace{50mu} {{{Antenna}\mspace{11mu} 1\mspace{11mu} {Antenna}\mspace{11mu} 2\mspace{11mu} {Antenna}\mspace{11mu} 3\mspace{14mu} {Antenna}\mspace{11mu} 4}{\begin{matrix}\begin{matrix}\begin{matrix}\underset{1}{Frequency} \\\underset{2}{Frequency}\end{matrix} \\\underset{3}{Frequency}\end{matrix} \\\underset{4}{Frequency}\end{matrix}\begin{bmatrix}S_{1} & 0 & {- S_{2}^{*}} & 0 \\S_{2} & 0 & S_{1}^{*} & 0 \\0 & S_{3} & 0 & {- S_{4}^{*}} \\0 & S_{4} & 0 & S_{3}^{*}\end{bmatrix}}}\mspace{31mu}} & (2)\end{matrix}$

In equation (2), each column indicates one transmission antenna and eachrow indicates one transmission frequency; S₁, S₂, S₃ and S₄ indicate thesymbols sent at the first, second, third and fourth time pointsrespectively, S₁*, S₂*, S₃*, and S₄* indicate the conjugates of S₁, S₂,S₃ and S₄ respectively.

With the continuous development of the LTE system, in order to increasethe data transmission rate and spectrum efficiency in the downlink inthe LTE-Advanced system, the related standards specify that at mosteight transmission antennae can be used. In the present LTE standards,however, the diversity method for the eight transmission antennae is notdefined, thus the data transmission based on eight transmission antennaecannot be implemented in the LTE-Advanced system so far, which bringsinconvenience to the practical applications.

SUMMARY OF THE INVENTION

Therefore, the main purpose of the present invention is to offer a spacediversity method and device to implement the data transmission based oneight antennae in the LTE-Advanced system and to acquire betterdiversity gain without adding extra pilot overhead.

In order to achieve the above purpose, the technical scheme of thepresent invention is implemented with the following method.

The present invention offers a space diversity method, and the methodcomprises:

setting the Alamouti-coder-based space-frequency block coder (SFBC) asthe minimum unit of the space time coder;

orthogonally processing the SFBC to acquire the transmission signals ofpart of antenna ports in the eight antenna ports, cyclically delayingthe acquired transmission signals of antenna ports to acquire thetransmission signals of the rest antenna ports; and

each antenna port transmitting the acquired transmission signal in thecorresponding time and subcarrier.

Said orthogonally processing the SFBC in the above scheme is:multiplying one Alamouti coder pair in the SFBC by a rotation factor sothat the Alamouti coder pair is orthogonal with another Alamouti coderpair when transmitting at the same time. Said rotation factor is e^(jθ),θε[0,2π].

In the above scheme, said acquiring the transmission signals of part ofthe antenna ports is: acquiring the transmission signal of four in theeight antenna ports; said cyclically delaying the acquired transmissionsignals of the antenna ports being phase rotation processing infrequency domain. Specifically, multiplying the acquired transmissionsignals of the four antenna ports by e^(j2πkτ/N) respectively to acquirethe transmission signals of the other four antenna ports, wherein, N isthe number of points in the inverse Fourier transform, k is the k^(th)subcarrier, and τ is the cyclic delay in each antenna port.

In the above scheme, the corresponding relationship between said eightantenna ports and the formed space time coder matrix is:

    Antenna  port  1  Antenna  port  2  Antenna  port  3  Antenna  port  4   Antenna  port  5  Antenna  port  6   Antenna  port  7  Antenna  port  8${\begin{matrix}\begin{matrix}\begin{matrix}\underset{k}{Subcarrier} \\\underset{k + 1}{Subcarrier}\end{matrix} \\\underset{k + 2}{Subcarrier}\end{matrix} \\\underset{k + 3}{Subcarrier}\end{matrix}\;\begin{bmatrix}S_{1} & {S_{1}^{{j2}\; \pi \; k\; {\tau_{1}/N}}} & {cS}_{3} & {{cS}_{3}^{{j2}\; \pi \; k\; {\tau_{1}/N}}} & {- S_{2}^{*}} & {{- S_{2}^{*}}^{{j2}\; \pi \; k\; {\tau_{1}/N}}} & {- S_{4}^{*}} & {{- S_{4}^{*}}^{{j2}\; \pi \; k\; {\tau_{1}/N}}} \\S_{2} & {S_{2}^{{j2}\; {\pi(\; {k + 1})}\; {\tau_{1}/N}}} & S_{4} & {S_{4}^{{j2}\; \pi \; {({k + 1})}\; {\tau_{1}/N}}} & S_{1}^{*} & {S_{1}^{*}^{{j2}\; \pi \; {({k + 1})}\; {\tau_{1}/N}}} & {c^{*}S_{3}^{*}} & {c^{*}S_{3}^{*}^{{j2}\; \pi \; {({k + 1})}\; {\tau_{1}/N}}} \\S_{3} & {S_{3}^{{j2}\; \pi \; {({k + 2})}\; {\tau_{1}/N}}} & {cS}_{1} & {{cS}_{1}^{{j2}\; \pi \; {({k + 2})}\; {\tau_{1}/N}}} & {- S_{4}^{*}} & {{- S_{4}^{*}}^{{j2}\; \pi \; {({k + 2})}\; {\tau_{1}/N}}} & {- S_{2}^{*}} & {{- S_{2}^{*}}^{{j2}\; \pi \; {({k + 2})}\; {\tau_{1}/N}}} \\S_{4} & {S_{4}^{{j2}\; \pi \; {({k + 3})}\; {\tau_{1}/N}}} & S_{2} & {S_{2}^{{j2}\; \pi \; {({k + 3})}{\tau_{1}/N}}} & S_{3}^{*} & {S_{3}^{*}^{{j2}\; \pi \; {({k + 3})}{\tau_{1}/N}}} & {c^{*}S_{1}^{*}} & {c^{*}S_{1}^{*}^{{j2}\; \pi \; {({k + 3})}{\tau_{1}/N}}}\end{bmatrix}}{\quad {{Or}\text{:}\mspace{50mu} {Antenna}\mspace{11mu} {port}\mspace{11mu} 1\mspace{14mu} {Antenna}\mspace{11mu} {port}\mspace{11mu} 2\mspace{14mu} {Antenna}\mspace{11mu} {port}\mspace{11mu} 3\mspace{14mu} {Antenna}\mspace{11mu} {port}\mspace{11mu} 4{\mspace{14mu} \;}{Antenna}\mspace{11mu} {port}\mspace{11mu} 5\mspace{11mu} {Antenna}\mspace{11mu} {port}\mspace{11mu} 6\mspace{20mu} {Antenna}\mspace{11mu} {port}\mspace{11mu} 7\mspace{20mu} {Antenna}\mspace{11mu} {port}\mspace{11mu} 8{\begin{matrix}\begin{matrix}\begin{matrix}\underset{k}{Subcarrier} \\\underset{k + 1}{Subcarrier}\end{matrix} \\\underset{k + 2}{Subcarrier}\end{matrix} \\\underset{k + 3}{Subcarrier}\end{matrix}\;\begin{bmatrix}S_{1} & {S_{1}^{{j2}\; \pi \; k\; {\tau_{1}/N}}} & S_{3} & {S_{3}^{{j2}\; \pi \; k\; {\tau_{1}/N}}} & {- S_{2}^{*}} & {{- S_{2}^{*}}^{{j2}\; \pi \; k\; {\tau_{1}/N}}} & {- {cS}_{4}^{*}} & {{- {cS}_{4}^{*}}^{{j2}\; \pi \; k\; {\tau_{1}/N}}} \\S_{2} & {S_{2}^{{j2}\; {\pi(\; {k + 1})}\; {\tau_{1}/N}}} & {cS}_{4} & {{cS}_{4}^{{j2}\; \pi \; {({k + 1})}\; {\tau_{1}/N}}} & S_{1}^{*} & {S_{1}^{*}^{{j2}\; \pi \; {({k + 1})}\; {\tau_{1}/N}}} & S_{3}^{*} & {S_{3}^{*}^{{j2}\; \pi \; {({k + 1})}\; {\tau_{1}/N}}} \\S_{3} & {S_{3}^{{j2}\; \pi \; {({k + 2})}\; {\tau_{1}/N}}} & S_{1} & {S_{1}^{{j2}\; \pi \; {({k + 2})}\; {\tau_{1}/N}}} & {- S_{4}^{*}} & {{- S_{4}^{*}}^{{j2}\; \pi \; {({k + 2})}\; {\tau_{1}/N}}} & {- {cS}_{2}^{*}} & {{- {cS}_{2}^{*}}^{{j2}\; \pi \; {({k + 2})}\; {\tau_{1}/N}}} \\S_{4} & {S_{4}^{{j2}\; \pi \; {({k + 3})}\; {\tau_{1}/N}}} & {cS}_{2} & {{cS}_{2}^{{j2}\; \pi \; {({k + 3})}{\tau_{1}/N}}} & S_{3}^{*} & {S_{3}^{*}^{{j2}\; \pi \; {({k + 3})}{\tau_{1}/N}}} & S_{1}^{*} & {S_{1}^{*}^{{j2}\; \pi \; {({k + 3})}{\tau_{1}/N}}}\end{bmatrix}}\quad}}$

In the above scheme, when said rotation factor is 1, said acquiring thetransmission signals of part of the antenna ports is: acquiring thetransmission signals of two in the eight antenna ports; said cyclicallydelaying the acquired transmission signals of the two antenna ports isphase rotation processing in frequency domain. Specifically, multiplyingthe acquired transmission signals of the two antenna ports by e^(j2πkτ)¹ ^(/N)

e^(j2πkτ) ² ^(/N) and e^(j2πkτ) ³ ^(/N) respectively to acquire thetransmission signals of the rest six antenna ports, wherein, N is thenumber of points in the inverse Fourier transform, k is the k^(th)subcarrier, and τ₁, τ₂ and τ₃ are the cyclic delays in different antennaport.

Accordingly, the corresponding relationship between the eight antennaports and the formed space time coder matrix is:

    Antenna  port  1  Antenna  port  2     Antenna  port  3   Antenna  port  4   Antenna  port  5  Antenna  port  6     Antenna  port  7     Antenna  port  8${\begin{matrix}\begin{matrix}\begin{matrix}\underset{k}{Subcarrier} \\\underset{k + 1}{Subcarrier}\end{matrix} \\\underset{k + 2}{Subcarrier}\end{matrix} \\\underset{k + 3}{Subcarrier}\end{matrix}\;\begin{bmatrix}S_{1} & {S_{1}^{{j2}\; \pi \; k\; {\tau_{1}/N}}} & {S_{1}^{{j2}\; \pi \; k\; {\tau_{2}/N}}} & {S_{1}^{{j2}\; \pi \; k\; {\tau_{3}/N}}} & {- S_{2}^{*}} & {{- S_{2}^{*}}^{{j2}\; \pi \; k\; {\tau_{1}/N}}} & {{- S_{2}^{*}}^{{j2}\; \pi \; k\; {\tau_{2}/N}}} & {{- S_{2}^{*}}^{{j2}\; \pi \; k\; {\tau_{3}/N}}} \\S_{2} & {S_{2}^{{j2}\; {\pi(\; {k + 1})}\; {\tau_{1}/N}}} & {S_{2}^{{j2}\; {\pi(\; {k + 1})}\; {\tau_{2}/N}}} & {S_{2}^{{j2}\; {\pi(\; {k + 1})}\; {\tau_{3}/N}}} & S_{1}^{*} & {S_{1}^{*}^{{j2}\; \pi \; {({k + 1})}\; {\tau_{1}/N}}} & {S_{1}^{*}^{{j2}\; \pi \; {({k + 1})}\; {\tau_{2}/N}}} & {S_{1}^{*}^{{j2}\; \pi \; {({k + 1})}\; {\tau_{3}/N}}} \\S_{3} & {S_{3}^{{j2}\; \pi \; {({k + 2})}\; {\tau_{1}/N}}} & {S_{3}^{{j2}\; \pi \; {({k + 2})}\; {\tau_{2}/N}}} & {S_{3}^{{j2}\; \pi \; {({k + 2})}\; {\tau_{3}/N}}} & {- S_{4}^{*}} & {{- S_{4}^{*}}^{{j2}\; \pi \; {({k + 2})}\; {\tau_{1}/N}}} & {{- S_{4}^{*}}^{{j2}\; \pi \; {({k + 2})}\; {\tau_{2}/N}}} & {{- S_{4}^{*}}^{{j2}\; \pi \; {({k + 2})}\; {\tau_{3}/N}}} \\S_{4} & {S_{4}^{{j2}\; \pi \; {({k + 3})}\; {\tau_{1}/N}}} & {S_{4}^{{j2}\; \pi \; {({k + 3})}\; {\tau_{2}/N}}} & {S_{4}^{{j2}\; \pi \; {({k + 3})}\; {\tau_{3}/N}}} & S_{3}^{*} & {S_{3}^{*}^{{j2}\; \pi \; {({k + 3})}{\tau_{1}/N}}} & {S_{3}^{*}^{{j2}\; \pi \; {({k + 3})}{\tau_{2}/N}}} & {S_{3}^{*}^{{j2}\; \pi \; {({k + 3})}{\tau_{3}/N}}}\end{bmatrix}}\quad$

The present invention also offers a space diversity device, and thedevice comprises an orthogonal processing module, a signal cyclic delaymodule and a transmitting module.

The orthogonal processing module is used to orthogonally process theSFBC to acquire the transmission signals of part of antenna ports in theeight antenna ports;

the signal cyclic delay module is used to cyclically delay the acquiredtransmission signals of the antenna ports to acquire the transmissionsignals of the rest antenna ports; and

the transmitting module is used to make each antenna port transmit theacquired transmission signal in the corresponding time and subcarrier.

The space diversity method and device offered in the present inventiontakes the SFBC based on the Alamouti coder as the minimum unit of thespace time coder, and orthogonally processes the SFBC to acquire thetransmission signals of part of antenna ports in the eight antennaports, and uses the diversity method for combining the Alamouti coderwith the cyclic delay diversity (CDD) to acquire the transmissionsignals of the rest antenna ports. Therefore, not only the datatransmission based on eight transmission antennae in the LTE-Advancedsystem is implemented, but also the frequency diversity and the encodinggain of the SFBC are implemented, moreover, the time diversity gain isobtained with the CDD, thus the diversity gain degradation due to thecorrelation of the transmission antenna array can be reduced.

By multiplying the rotation factor of the SFBC, the present inventionmaintains the orthogonality of the transmitted symbols, increases thetimes of transmitting the symbols, as well as improves the diversitygain.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a flow chart of achieving the space diversity method inaccordance with the present invention;

FIG. 2 is a structure schematic diagram of composition of the spacediversity device in accordance with the present invention.

PREFERRED EMBODIMENTS OF THE PRESENT INVENTION

The basic idea of the present invention is: setting the SFBC based onAlamouti coder as the minimum unit of the space time coder, orthogonallyprocessing the SFBC to acquire the transmission signals of part ofantenna ports in the eight antenna ports, and cyclically delaying theacquired transmission signals of the antenna ports to acquire thetransmission signals of the rest antenna ports, each antenna porttransmitting the acquired transmission signal in the corresponding timeand subcarrier.

Therefore, eight antennae diversity in the downlink in the LTE-Advancedsystem combines the SFBC and CDD, and different symbols correspond todifferent antennae, thus avoid the diversity gain degradation due to theantenna correlation, implement multi-dimensional diversity gain andmaintain the orthogonality of the transmission signals.

In the present invention, the eight antenna ports form an eight-antennaarray, and each antenna port represents an antenna. During theorthogonally processing and cyclically delaying processing, four or twoin the eight antenna ports are taken as a group to be processed.

The process of implementing the CDD based space diversity method inaccordance with the present invention is shown in FIG. 1, and the methodcomprises the following steps.

Step 101: set the SFBC based on the Alamouti coder as the minimum unitof the space time coder.

Since when the rank of the wireless channel is 1, the Alamouti spacetime coder method can reach to the channel capacity and acquire themaximum diversity gain, moreover, since the Alamouti codec is simple andcan achieve the full diversity gain, the present invention takes theSFBC based on the Alamouti coder as the minimum unit of the space timecoder.

Step 102: orthogonally process the SFBC to acquire the transmissionsignals of part of antenna ports in the eight antenna ports.

Herein, said orthogonal processing is multiplying one Alamouti coderpair in the SFBC by a rotation factor c=e^(jθ), θε[0,2π] to make itorthogonal with another Alamouti coder pair when transmitting at thesame time. Especially, the rotation factor equals 1.

When four in the eight antenna ports are taken as a group, saidacquiring part of the antenna ports is acquiring the transmissionsignals of the four antenna ports; when two in the eight antenna portsare taken as a group, said acquiring part of the antenna ports isacquiring the transmission signals of two antenna ports.

Step 103: cyclically delay the acquired transmission signals of theantenna ports to acquire the transmission signals of the rest antennaports.

Herein, said cyclically delaying the acquired transmission signals ofthe antenna ports is equivalent to the phase rotation processing infrequency domain.

When four in the eight antenna ports are taken as a group, saidacquiring the rest antenna ports is acquiring the transmission signalsof the rest four antenna ports; when two in the eight antenna ports aretaken as a group, said acquiring the rest antenna ports is acquiring thetransmission signals of the rest six antenna ports.

Step 104: each antenna port transmits the acquired transmission signalsin the corresponding time and subcarrier.

The First Embodiment

In this embodiment, four in the eight antenna ports are taken as agroup. The space diversity method of the present embodiment comprisesthe following steps.

Step 11: set the SFBC based on the Alamouti coder as the minimum unit ofthe space time coder;

Step 12: orthogonally process the SFBC to acquire the transmissionsignals of the four antenna ports.

For the SFBC based on the Alamouti coder, the Alamouti encoder whenusing four antennae to transmit at the same time is shown in Equation(3):

$\begin{matrix}\begin{bmatrix}S_{1} & {cS}_{3} & {- S_{2}^{*}} & {- S_{4}^{*}} \\S_{2} & S_{4} & S_{1}^{*} & {c^{*}S_{3}^{*}} \\S_{3} & {cS}_{1} & {- S_{4}^{*}} & {- S_{2}^{*}} \\S_{4} & S_{2} & S_{3}^{*} & {c^{*}S_{1}^{*}}\end{bmatrix} & (3)\end{matrix}$

Herein, by processing the SFBC with the rotation factor, the twoAlamouti coder pairs

$\begin{bmatrix}S_{1} & {- S_{2}^{*}} \\S_{2} & S_{1}^{*}\end{bmatrix}\mspace{14mu} {{and}\mspace{14mu}\begin{bmatrix}S_{3} & {- S_{4}^{*}} \\S_{4} & S_{3}^{*}\end{bmatrix}}$

are orthogonal with each other when transmitting at the same time.

Specifically, multiply the second Alamouti coder pair

$\begin{bmatrix}S_{3} & {- S_{4}^{*}} \\S_{4} & S_{3}^{*}\end{bmatrix}\quad$

with a rotation factor c=e^(jθ), θε[0,2π] to be

$\begin{bmatrix}{cS}_{3} & {- S_{4}^{*}} \\S_{4} & {c^{*}S_{3}^{*}}\end{bmatrix},$

therefore, it is orthogonal with the first Alamouti coder pair

$\begin{bmatrix}S_{1} & {- S_{2}^{*}} \\S_{2} & S_{1}^{*}\end{bmatrix}\quad$

when transmitting at the same time, and good diversity gain can bemaintained. Of course, the first Alamouti coder pair

$\begin{bmatrix}S_{1} & {- S_{2}^{*}} \\S_{2} & S_{1}^{*}\end{bmatrix}\quad$

can be multiplied by a rotation factor c to become

$\begin{bmatrix}{cS}_{1} & {- S_{2}^{*}} \\S_{2} & {c^{*}S_{1}^{*}}\end{bmatrix}\quad$

so that it is orthogonal with the second Alamouti coder

$\begin{bmatrix}S_{3} & {- S_{4}^{*}} \\S_{4} & S_{3}^{*}\end{bmatrix}\quad$

when transmitting at the same time.

Each column in Equation (3) is the transmission signal of one antennaport.

Step 13: cyclically delay the acquired transmission signals of the fourantenna ports to acquire the transmission signals of the antenna portsadjacent to said four antenna ports respectively.

Herein, since the LTE-Advanced system uses eight antennae to transmit,when there is an eight-antenna array, the interval between the antennaeis usually half of a wavelength at the antenna transmission frequency,in this case, the correlation of the transmission antenna array is verystrong, in comparison with the LTE diversity technology (see 3GPPR-071333), however, it has proved that the antenna correlation has noevident effect on the CDD diversity gain. Therefore, the presentinvention cyclically delays the Alamouti coder on the basis of fourantennae, and uses the diversity method for combining the CDD with theAlamouti coder. This diversity method comprises: using the signals offour antennae as the transmission signals of four in the eight antennaports; cyclically delaying the available transmission signals of thefour antenna ports by τ

, τ₁≠0 to acquire the transmission signals of the other four antennae;taking the acquired other four antenna ports as the adjacent antennae ofthe available four antenna ports respectively.

Two specific examples of the corresponding relationship between thespace time coder matrix and the transmission antenna ports based on theabove method are illustrated in the following, and the firstcorresponding relationship is shown in Equation (4), and the secondcorresponding relationship is shown in Equation (5).

$\begin{matrix}\overset{\mspace{79mu} {{Antenna}\mspace{14mu} {port}\mspace{11mu} 1\mspace{14mu} {Antenna}\mspace{14mu} {port}\mspace{11mu} 2\mspace{14mu} {Antenna}\mspace{14mu} {port}\mspace{11mu} 3\mspace{20mu} {Antenna}\mspace{14mu} {port}\mspace{11mu} 4\mspace{14mu} {Antenna}\mspace{14mu} {port}\mspace{11mu} 5\mspace{11mu} {Antenna}\mspace{14mu} {port}\mspace{14mu} 6{\mspace{11mu} \mspace{14mu}}{Antenna}\mspace{14mu} {port}\mspace{11mu} 7{\mspace{11mu} \mspace{20mu}}{Antenna}\mspace{14mu} {port}\mspace{11mu} 8}}{{\begin{matrix}\begin{matrix}\begin{matrix}\underset{k}{Subcarrier} \\\underset{k + 1}{Subcarrier}\end{matrix} \\\underset{k + 2}{Subcarrier}\end{matrix} \\\underset{k + 3}{Subcarrier}\end{matrix}\mspace{14mu}\begin{bmatrix}S_{1} & {S_{1}^{{j2\pi}\; k\; {\tau_{1}/N}}} & {cS}_{3} & {{cS}_{3}^{{j2\pi}\; k\; {\tau_{1}/N}}} & {- S_{2}^{*}} & {{- S_{2}^{*}}^{{j2}\; \pi \; k\; {\tau_{1}/N}}} & {- S_{4}^{*}} & {{- S_{4}^{*}}^{{j2\pi}\; k\; {\tau_{1}/N}}} \\S_{2} & {S_{2}^{{{j2\pi}{({k + 1})}}{\tau_{1}/N}}} & S_{4} & {S_{4}^{{j2\pi}\; {({k + 1})}\; {\tau_{1}/N}}} & S_{1}^{*} & {S_{1}^{*}^{{j2}\; \pi \; {({k + 1})}\; {\tau_{1}/N}}} & {c^{*}S_{3}^{*}} & {c^{*}S_{3}^{*}^{{{j2\pi}{({k + 1})}}{\tau_{1}/N}}} \\S_{3} & {S_{3}^{{{j2\pi}{({k + 2})}}{\tau_{1}/N}}} & {cS}_{1} & {{cS}_{1}^{{j2\pi}\; {({k + 2})}\; {\tau_{1}/N}}} & {- S_{4}^{*}} & {{- S_{4}^{*}}^{{j2}\; \pi \; {({k + 2})}\; {\tau_{1}/N}}} & {- S_{2}^{*}} & {{- S_{2}^{*}}^{{{j2\pi}{({k + 2})}}{\tau_{1}/N}}} \\S_{4} & {S_{4}^{{{j2\pi}{({k + 3})}}{\tau_{1}/N}}} & S_{2} & {S_{2}^{{j2\pi}\; {({k + 3})}\; {\tau_{1}/N}}} & S_{3}^{*} & {S_{3}^{*}^{{j2}\; \pi \; {({k + 3})}\; {\tau_{1}/N}}} & {c^{*}S_{1}^{*}} & {c^{*}S_{1}^{*}^{{{j2\pi}{({k + 3})}}{\tau_{1}/N}}}\end{bmatrix}}\quad} & (4)\end{matrix}$

In Equation (4), each column represents one antenna port and each rowrepresents a subcarrier sent by the space time coder symbol or anorthogonal frequency division multiplexing (OFDM) symbol. N ine^(j2πkτ/N) in Equation (4) is the number of points in the inverseFourier transform, and k represents the k^(th) subcarrier, k=1 . . . N.Time delaying τ, τε[0,2Nπ) in each antenna port in time domain isequivalent to kτ/N in each subcarrier in frequency domain; that is,multiplying the acquired transmission signals of the four antenna portsby e^(j2πkτ/N) respectively. Specifically, antenna port 1, antenna port3, antenna port 5 and antenna port 7 form Alamouti coders which areorthogonal and sent evenly and distributively, and cyclically delay theAlamouti coders of antenna port 1, antenna port 3, antenna port 5 andantenna port 7 by τ

, τ

≠0 to form the signals transmitted at antenna port 2, antenna port 4,antenna port 6 and antenna port 8, since the signals transmitted atantenna port 2, antenna port 4, antenna port 6 and antenna port 8 aredelayed by τ₁ at the same time, the orthogonality of the Alamouti coderscan still be maintained.

Another corresponding relationship between the space time coder matrixand the transmission antenna ports can be formed if the rotation factoris multiplied by different symbols in the Alamouti coder pair:

$\begin{matrix}\overset{\mspace{25mu} {{Antenna}\mspace{14mu} {port}\mspace{14mu} 1\mspace{25mu} {Antenna}\mspace{14mu} {port}\mspace{14mu} 2\mspace{25mu} {Antenna}\mspace{14mu} {port}\mspace{14mu} 3\mspace{25mu} {Antenna}\mspace{14mu} {port}\mspace{14mu} 4\mspace{25mu} {Antenna}\mspace{14mu} {port}\mspace{14mu} 5\mspace{25mu} {Antenna}\mspace{14mu} {port}\mspace{14mu} 6\mspace{25mu} {Antenna}\mspace{14mu} {port}\mspace{14mu} 7\mspace{25mu} {Antenna}\mspace{14mu} {port}\mspace{14mu} 8}}{{\begin{matrix}\begin{matrix}\begin{matrix}\underset{k}{Subcarrier} \\\underset{k + 1}{Subcarrier}\end{matrix} \\\underset{k + 2}{Subcarrier}\end{matrix} \\\underset{k + 3}{Subcarrier}\end{matrix}\mspace{20mu}\begin{bmatrix}S_{1} & {S_{1}^{{j2\pi}\; k\; {\tau_{1}/N}}} & S_{3} & {S_{3}^{{j2\pi}\; k\; {\tau_{1}/N}}} & {- S_{2}^{*}} & {{- S_{2}^{*}}^{{j2}\; \pi \; k\; {\tau_{1}/N}}} & {{- c^{*}}S_{4}^{*}} & {{- {cS}_{4}^{*}}^{{j2\pi}\; k\; {\tau_{1}/N}}} \\S_{2} & {S_{2}^{{{j2\pi}{({k + 1})}}{\tau_{1}/N}}} & {cS}_{4} & {{cS}_{4}^{{j2\pi}\; {({k + 1})}\; {\tau_{1}/N}}} & S_{1}^{*} & {S_{1}^{*}^{{j2}\; \pi \; {({k + 1})}\; {\tau_{1}/N}}} & S_{3}^{*} & {S_{3}^{*}^{{{j2\pi}{({k + 1})}}{\tau_{1}/N}}} \\S_{3} & {S_{3}^{{{j2\pi}{({k + 2})}}{\tau_{1}/N}}} & S_{1} & {S_{1}^{{j2\pi}\; {({k + 2})}\; {\tau_{1}/N}}} & {- S_{4}^{*}} & {{- S_{4}^{*}}^{{j2}\; \pi \; {({k + 2})}\; {\tau_{1}/N}}} & {{- c^{*}}S_{2}^{*}} & {{- c^{*}}S_{2}^{*}^{{{j2\pi}{({k + 2})}}{\tau_{1}/N}}} \\S_{4} & {S_{4}^{{{j2\pi}{({k + 3})}}{\tau_{1}/N}}} & {cS}_{2} & {{cS}_{2}^{{j2\pi}\; {({k + 3})}\; {\tau_{1}/N}}} & S_{3}^{*} & {S_{3}^{*}^{{j2}\; \pi \; {({k + 3})}\; {\tau_{1}/N}}} & S_{1}^{*} & {S_{1}^{*}^{{{j2\pi}{({k + 3})}}{\tau_{1}/N}}}\end{bmatrix}}\quad} & (5)\end{matrix}$

In Equation (5), each column represents an antenna port and each rowrepresents a subcarrier sent by the space time coder symbol or an OFDMsymbol. N in e^(j2πkτ/N) in Equation (5) is the number of points in theinverse Fourier transform, and k represents the k^(th) subcarrier, andk=1 . . . N. Time delaying τ

τε[0,2Nπ) in each antenna port in time domain is equivalent to phaserotation kτ/N in each subcarrier in frequency domain; that is,multiplying the acquired transmission signals of the four antenna portsby e^(j2πkτ/N). Specifically, antenna port 1, antenna port 3, antennaport 5 and antenna port 7 form the Alamouti coders which are orthogonaland sent evenly and distributively, and cyclically delay the Alamouticoders of antenna port 1, antenna port 3, antenna port 5 and antennaport 7 by τ₁

τ₁≠0 to form the signals transmitted at antenna port 2, antenna port 4,antenna port 6 and antenna port 8, since the signals transmitted atantenna port 2, antenna port 4, antenna port 6 and antenna port 8 aredelayed by τ₁, the orthogonality of the Alamouti coder can still bemaintained.

In practical applications, the cyclic delay of antenna port 1, antennaport 3, antenna port 5 and antenna 7 can be the same, for example, thedelay is τ₁; alternatively, the delays for antenna port 1, antenna port3, antenna port 5 and antenna port 7 can also be different, as long asperform the same cyclic delay for the antenna ports in the same group.For example, cyclically delay antenna port 1 and antenna port 3 τ₁, andcyclically delay antenna port 5 and antenna port 7 by τ₂, τ₁≠τ₂.

Step 14: each antenna port transmits the acquired transmission signal inthe corresponding time and subcarrier.

Herein, said acquired transmission signals refer to the orthogonallyprocessed signals, such as the signals of antenna port 1, antenna port3, antenna port 5 and antenna port 7; or the orthogonally processed andcyclically delayed signals, such as the signals of antenna port 2,antenna port 4, antenna port 6 and antenna port 8. Each antenna port cantransmit the corresponding signal in the corresponding time andsubcarrier according to the corresponding relationship given in equation(4) or (5).

For example, antenna port 1 transmits signal S₁ in the subcarrier k inthe first time; antenna port 1 transmits signal S₂ in the subcarrier k+1in the second time; antenna port 1 transmits signal S₃ in the subcarrierk+2 in the third time; antenna port 1 transmits signal S₄ in thesubcarrier k+3 in the fourth time; antenna port 2 transmits signalS₁e^(j2πkτ)

^(/N) in the subcarrier k at the time of the first time+delay τ₁;antenna port 2 transmits signal S₂ e^(j2π(k+1)τ)

^(/N) in the subcarrier k+1 at the time of the second time+delay τ

; antenna port 2 transmits signal S₃e^(j2π(k+2)τ)

^(/N) in the subcarrier k+2 at the time of the third time+delay τ

; antenna port 2 transmits signal S₂e^(j2π)

^(/N) in the subcarrier k+3 at the time of the fourth time+τ₁, and soforth.

The Second Embodiment

In this embodiment, two in the eight antenna ports are taken as a group,and the rotation factor is 1. The space diversity method of thisembodiment comprises the following steps:

Step 21: set the SFBC based on the Alamouti coder as the minimum unit ofthe space time coder;

Step 22: orthogonally process the SFBC to acquire the transmissionsignals of two antenna ports.

Herein, said orthogonally processing means processing the SFBC with therotation factor, and the rotation factor equals 1.

Step 23: cyclically delay the acquired transmission signals of the twoantenna ports to acquire the transmission signals of the other sixantenna ports.

Wherein, said cyclically delaying is equivalent to phase rotationprocessing in frequency domain, specifically, multiply the acquiredtransmissions signals of the two antenna ports by e^(j2πkτ) ¹ ^(/N)

e^(j2πkτ) ² ^(/N) and e^(j2πkτ) ³ ^(/N) respectively to acquire thetransmission signals of the other six antenna ports.

Herein, said acquired corresponding relationship between the space timecoder matrix and the transmission antenna ports is shown in equation(6):

$\begin{matrix}\overset{\mspace{76mu} {{Antenna}\mspace{14mu} {port}\mspace{14mu} 1\mspace{50mu} {Antenna}\mspace{14mu} {port}\mspace{14mu} 2\mspace{50mu} {Antenna}\mspace{14mu} {port}\mspace{14mu} 3\mspace{50mu} {Antenna}\mspace{14mu} {port}\mspace{14mu} 4\mspace{50mu} {Antenna}\mspace{14mu} {port}\mspace{14mu} 5\mspace{56mu} {Antenna}\mspace{14mu} {port}\mspace{14mu} 6\mspace{50mu} {Antenna}\mspace{14mu} {port}\mspace{14mu} 7\mspace{50mu} {Antenna}\mspace{14mu} {port}\mspace{14mu} 8}}{\begin{matrix}\begin{matrix}\begin{matrix}\underset{k}{Subcarrier} \\\underset{k + 1}{Subcarrier}\end{matrix} \\\underset{k + 2}{Subcarrier}\end{matrix} \\\underset{k + 3}{Subcarrier}\end{matrix}\mspace{20mu}\begin{bmatrix}S_{1} & {S_{1}^{{j2\pi}\; k\; {\tau_{1}/N}}} & {S_{1}^{{j2\pi}\; k\; {\tau_{2}/N}}} & {S_{1}^{{j2\pi}\; k\; {\tau_{3}/N}}} & {- S_{2}^{*}} & {{- S_{2}^{*}}^{{j2}\; \pi \; k\; {\tau_{1}/N}}} & {{- S_{2}^{*}}^{{j2}\; \pi \; k\; {\tau_{2}/N}}} & {{- S_{2}^{*}}^{{j2\pi}\; k\; {\tau_{3}/N}}} \\S_{2} & {S_{2}^{{{j2\pi}{({k + 1})}}{\tau_{1}/N}}} & {S_{2}^{{{j2\pi}{({k + 1})}}{\tau_{2}/N}}} & {S_{2}^{{j2\pi}\; {({k + 1})}\; {\tau_{3}/N}}} & S_{1}^{*} & {S_{1}^{*}^{{j2}\; \pi \; {({k + 1})}\; {\tau_{1}/N}}} & {S_{1}^{*}^{{j2}\; \pi \; {({k + 1})}\; {\tau_{2}/N}}} & {S_{1}^{*}^{{{j2\pi}{({k + 1})}}{\tau_{3}/N}}} \\S_{3} & {S_{3}^{{{j2\pi}{({k + 2})}}{\tau_{1}/N}}} & {S_{3}^{{{j2\pi}{({k + 2})}}{\tau_{2}/N}}} & {S_{3}^{{j2\pi}\; {({k + 2})}\; {\tau_{3}/N}}} & {- S_{4}^{*}} & {{- S_{4}^{*}}^{{j2}\; \pi \; {({k + 2})}\; {\tau_{1}/N}}} & {{- S_{4}^{*}}^{{j2}\; \pi \; {({k + 2})}\; {\tau_{2}/N}}} & {{- S_{4}^{*}}^{{{j2\pi}{({k + 2})}}{\tau_{3}/N}}} \\S_{4} & {S_{4}^{{{j2\pi}{({k + 3})}}{\tau_{1}/N}}} & {S_{4}^{{{j2\pi}{({k + 3})}}{\tau_{2}/N}}} & {S_{4}^{{j2\pi}\; {({k + 3})}\; {\tau_{3}/N}}} & S_{3}^{*} & {S_{3}^{*}^{{j2}\; \pi \; {({k + 3})}\; {\tau_{1}/N}}} & {S_{3}^{*}^{{j2}\; \pi \; {({k + 3})}\; {\tau_{2}/N}}} & {S_{3}^{*}^{{{j2\pi}{({k + 3})}}{\tau_{3}/N}}}\end{bmatrix}} & (6)\end{matrix}$

In equation (6), each column represents one antenna port and each columnrepresents a subcarrier sent by the space time coder symbol or an OFDMsymbol. N in Equation (6) is the number of points in the inverse Fouriertransform, and k represents the k^(th) subcarrier, k=1 . . . N. Timedelaying τ₁, τ₂ or τ₃, τ₁z,40 τ₂

τ₃

ε[0,2Nπ) in each antenna port in time domain is equivalent to phaserotation kτ/N in each subcarrier in frequency domain, that is,multiplying the acquired transmission signals of the two antenna portsby e^(j2πkτ) ¹ ^(/N)

e^(j2πkτ) ² ^(/N) and e^(j2πkτ) ³ ^(/N) respectively.

The present embodiment forms two Alamouti coders

$\begin{bmatrix}S_{1} & {- S_{2}^{*}} \\S_{2} & S_{1}^{*}\end{bmatrix}\mspace{14mu} {{and}\mspace{14mu}\begin{bmatrix}S_{3} & {- S_{4}^{*}} \\S_{4} & S_{3}^{*}\end{bmatrix}}$

at antenna port 1 and antenna port 5 respectively, antenna port 2 andantenna port 6 cyclically delay the two Alamouti coder pairs by τ₁, thatis, multiplying the two Alamouti coder pairs by e^(j2πkτ)

^(/N); antenna port 3 and antenna port 7 cyclically delay both Alamouticoder pair by τ₂, that is, multiplying the two Alamouti coder pairs bye^(j2πkτ) ² ^(/N); antenna port 4 and antenna port 8 cyclically delayboth Alamouti coder pair by τ₃, that is, multiplying the two Alamouticoder pairs by e^(j2πkτ)

^(/N).

In order to implement the above method, as shown in FIG. 2, the presentinvention also offers a space diversity device, and the device comprisesan orthogonal processing module 21, a signal cyclic delay module 22 anda transmitting module 23.

The orthogonal processing module 21 is used to orthogonally process theSFBC to acquire the transmission signals of part of antenna ports in theeight antenna ports. Herein, said orthogonal processing is multiplyingone Alamouti coder pair in the SFBC with a rotation factor c=e^(jθ),θε[0,2π] so as to make it orthogonal with the other Alamouti coder whentransmitting at the same time; especially, the rotation factor c is 1.

The signal cyclic delay module 22 is used to cyclically delay theacquired transmission signals of the antenna ports to acquire thetransmission signals of the rest antenna ports. Herein, the acquiredtransmission signals of the antenna ports are the acquired transmissionsignals processed by the orthogonal processing module 21, and what areacquired can be the transmission signals of four or two antenna ports.

With the above orthogonal processing or the orthogonal processing pluscyclically delaying processing, the transmission signals of the eightantenna ports respectively in different carriers can be acquired, andthe corresponding relationships between each transmission antenna portand the space time coder matrix is shown in equation (4), equation (5)or equation (6).

The transmission module 23 is used to make each antenna port transmitthe acquired transmission signal in the corresponding time andsubcarrier. Herein, each antenna port can transmit the correspondingsignal in the corresponding time and subcarrier according to thecorresponding relationship given in equation (4), equation (5) orequation (6).

The above embodiments are only the preferred embodiments of the presentinvention, not intended to limit the protection scope of the presentinvention, and the present invention can be modified, replacedequivalently or improved without departing from the spirit and principleof the present invention, and all these kinds of modification,equivalent replacement or improvement should belong to the protectionscope of the present invention.

INDUSTRIAL APPLICABILITY

The space diversity method and device offered in the present inventionnot only implement the data transmission based on eight transmissionantennae in the LTE-Advanced system, but also implement the frequencydiversity and the coder gain of the SFBC, moreover, the time diversitygain is acquired by the CDD, thus the diversity gain degradation due tothe transmission antenna array channel correlation can be reducedwithout adding extra pilot overhead. By multiplying the rotation factorof the SFBC, the present invention maintains the orthogonality of thetransmitted symbols, increases the times of transmitting the symbols,and improves the diversity gain.

1. A space diversity method, comprising: setting an Alamouti-coder-basedspace frequency block coder as a minimum unit of a space time coder;orthogonally processing the space frequency block coder to acquiretransmission signals of part of antenna ports in eight antenna ports,and cyclically delaying the acquired transmission signals of antennaports to acquire the transmission signals of the rest antenna ports; andeach antenna port transmitting the acquired transmission signal in acorresponding time and subcarrier.
 2. The space diversity method ofclaim 1, wherein, said orthogonally processing the space frequency blockcoder is: multiplying one Alamouti coder pair in the space frequencyblock coder by a rotation factor so that the Alamouti coder pair isorthogonal with another Alamouti coder pair when transmitting at thesame time.
 3. The space diversity method of claim 2, wherein, saidrotation factor is e^(jθ), θε[0,2π].
 4. The space diversity method ofclaim 3, wherein, said acquiring the transmission signals of part of theantenna ports is: acquiring the transmission signals of four antennaports in the eight antenna ports; and said cyclically delaying theacquired transmission signals of the antenna ports is phase rotationprocessing in frequency domain, and said phase rotation processing is:multiplying the acquired transmission signals of the four antenna portsby e^(j2πkτ/N) respectively to acquire the transmission signals of therest four antenna ports, wherein, N is the number of points in inverseFourier transform, k represents a k^(th) subcarrier, and τ is a cyclicdelay in each antenna port.
 5. The space diversity method of claim 4,wherein, a corresponding relationship between said eight antenna portsand a formed space time coder matrix is: $\begin{matrix}{\overset{\mspace{59mu} {{Antenna}\mspace{14mu} {port}\mspace{14mu} 1\mspace{14mu} {Antenna}\mspace{14mu} {port}\mspace{14mu} 2\mspace{14mu} {Antenna}\mspace{14mu} {port}\mspace{14mu} 3\mspace{20mu} {Antenna}\mspace{14mu} {port}\mspace{14mu} 4\mspace{14mu} {Antenna}\mspace{14mu} {port}\mspace{14mu} 5\mspace{11mu} {Antenna}\mspace{14mu} {port}\mspace{14mu} 6{\mspace{11mu} \mspace{14mu}}{Antenna}\mspace{14mu} {port}\mspace{14mu} 7{\mspace{11mu} \mspace{20mu}}{Antenna}\mspace{14mu} {port}\mspace{14mu} 8}}{{\begin{matrix}\begin{matrix}\begin{matrix}\underset{k}{Subcarrier} \\\underset{k + 1}{Subcarrier}\end{matrix} \\\underset{k + 2}{Subcarrier}\end{matrix} \\\underset{k + 3}{Subcarrier}\end{matrix}\mspace{20mu}\begin{bmatrix}S_{1} & {S_{1}^{{j2\pi}\; k\; {\tau_{1}/N}}} & {cS}_{3} & {{cS}_{3}^{{j2\pi}\; k\; {\tau_{1}/N}}} & {- S_{2}^{*}} & {{- S_{2}^{*}}^{{j2}\; \pi \; k\; {\tau_{1}/N}}} & {- S_{4}^{*}} & {{- S_{4}^{*}}^{{j2\pi}\; k\; {\tau_{1}/N}}} \\S_{2} & {S_{2}^{{{j2\pi}{({k + 1})}}{\tau_{1}/N}}} & S_{4} & {S_{4}^{{j2\pi}\; {({k + 1})}\; {\tau_{1}/N}}} & S_{1}^{*} & {S_{1}^{*}^{{j2}\; \pi \; {({k + 1})}\; {\tau_{1}/N}}} & {c^{*}S_{3}^{*}} & {c^{*}S_{3}^{*}^{{{j2\pi}{({k + 1})}}{\tau_{1}/N}}} \\S_{3} & {S_{3}^{{{j2\pi}{({k + 2})}}{\tau_{1}/N}}} & {cS}_{1} & {{cS}_{1}^{{j2\pi}\; {({k + 2})}\; {\tau_{1}/N}}} & {- S_{4}^{*}} & {{- S_{4}^{*}}^{{j2}\; \pi \; {({k + 2})}\; {\tau_{1}/N}}} & {- S_{2}^{*}} & {{- S_{2}^{*}}^{{{j2\pi}{({k + 2})}}{\tau_{1}/N}}} \\S_{4} & {S_{4}^{{{j2\pi}{({k + 3})}}{\tau_{1}/N}}} & S_{2} & {S_{2}^{{j2\pi}\; {({k + 3})}\; {\tau_{1}/N}}} & S_{3}^{*} & {S_{3}^{*}^{{j2}\; \pi \; {({k + 3})}\; {\tau_{1}/N}}} & {c^{*}S_{1}^{*}} & {c^{*}S_{1}^{*}^{{{j2\pi}{({k + 3})}}{\tau_{1}/N}}}\end{bmatrix}}\quad}{{Or}\text{:}}\begin{matrix}\overset{\mspace{56mu} {{Antenna}\mspace{14mu} {port}\mspace{14mu} 1\mspace{14mu} {Antenna}\mspace{14mu} {port}\mspace{14mu} 2\mspace{14mu} {Antenna}\mspace{14mu} {port}\mspace{14mu} 3\mspace{14mu} {Antenna}\mspace{14mu} {port}\mspace{14mu} 4\mspace{14mu} {Antenna}\mspace{14mu} {port}\mspace{14mu} 5{\mspace{11mu} \;}{Antenna}\mspace{14mu} {port}\mspace{14mu} 6{\mspace{11mu} \mspace{20mu}}{Antenna}\mspace{14mu} {port}\mspace{14mu} 7{\mspace{11mu} \mspace{20mu}}{Antenna}\mspace{14mu} {port}\mspace{14mu} 8}}{{\begin{matrix}\begin{matrix}\begin{matrix}\underset{k}{Subcarrier} \\\underset{k + 1}{Subcarrier}\end{matrix} \\\underset{k + 2}{Subcarrier}\end{matrix} \\\underset{k + 3}{Subcarrier}\end{matrix}\mspace{20mu}\begin{bmatrix}S_{1} & {S_{1}^{{j2\pi}\; k\; {\tau_{1}/N}}} & S_{3} & {S_{3}^{{j2\pi}\; k\; {\tau_{1}/N}}} & {- S_{2}^{*}} & {{- S_{2}^{*}}^{{j2}\; \pi \; k\; {\tau_{1}/N}}} & {- {cS}_{4}^{*}} & {{- {cS}_{4}^{*}}^{{j2\pi}\; k\; {\tau_{1}/N}}} \\S_{2} & {S_{2}^{{{j2\pi}{({k + 1})}}{\tau_{1}/N}}} & {cS}_{4} & {{cS}_{4}^{{j2\pi}\; {({k + 1})}\; {\tau_{1}/N}}} & S_{1}^{*} & {S_{1}^{*}^{{j2}\; \pi \; {({k + 1})}\; {\tau_{1}/N}}} & S_{3}^{*} & {S_{3}^{*}^{{{j2\pi}{({k + 1})}}{\tau_{1}/N}}} \\S_{3} & {S_{3}^{{{j2\pi}{({k + 2})}}{\tau_{1}/N}}} & S_{1} & {S_{1}^{{j2\pi}\; {({k + 2})}\; {\tau_{1}/N}}} & {- S_{4}^{*}} & {{- S_{4}^{*}}^{{j2}\; \pi \; {({k + 2})}\; {\tau_{1}/N}}} & {- {cS}_{2}^{*}} & {{- {cS}_{2}^{*}}^{{{j2\pi}{({k + 2})}}{\tau_{1}/N}}} \\S_{4} & {S_{4}^{{{j2\pi}{({k + 3})}}{\tau_{1}/N}}} & {cS}_{2} & {{cS}_{2}^{{j2\pi}\; {({k + 3})}\; {\tau_{1}/N}}} & S_{3}^{*} & {S_{3}^{*}^{{j2}\; \pi \; {({k + 3})}\; {\tau_{1}/N}}} & S_{1}^{*} & {S_{1}^{*}^{{{j2\pi}{({k + 3})}}{\tau_{1}/N}}}\end{bmatrix}}\quad} & \;\end{matrix}} & \;\end{matrix}$ wherein, k represents the k^(th) subcarrier, is the cyclicdelay, kτ/N is the phase rotation, and N in e^(j2πkτ/N) is the number ofpoints in the inverse Fourier transform.
 6. The space diversity methodof claim 2, wherein, said rotation factor is
 1. 7. The space diversitymethod of claim 6, wherein, said acquiring the transmission signals ofpart of the antenna ports is: acquiring the transmission signals of twoantenna ports in the eight antenna ports; and said cyclically delayingthe acquired transmission signals of the antenna ports is phase rotationprocessing in frequency domain, said phase rotation processing is:multiplying the acquired transmission signals of the two antenna portsby e^(j2πkτ) ¹ ^(/N)

e^(j2πkτ) ² ^(/N) and e^(j2πkτ) ³ ^(/N) respectively to acquire thetransmission signals of the rest six antenna ports, wherein, N is thenumber of points in inverse Fourier transform, k represents a k^(th)subcarrier, and τ₁, τ₂ and τ₃ are cyclic delays in different antennaports.
 8. The space diversity method of claim 7, wherein, acorresponding relationship between the eight antenna ports and a formedspace time coder matrix is: $\begin{matrix}\overset{\mspace{56mu} {{Antenna}\mspace{14mu} {port}\mspace{14mu} 1\mspace{34mu} {Antenna}\mspace{14mu} {port}\mspace{14mu} 2\mspace{34mu} {Antenna}\mspace{14mu} {port}\mspace{14mu} 3\mspace{45mu} {Antenna}\mspace{14mu} {port}\mspace{14mu} 4\mspace{34mu} {Antenna}\mspace{14mu} {port}\mspace{14mu} 5\mspace{40mu} {Antenna}\mspace{14mu} {port}\mspace{14mu} 6\mspace{45mu} {Antenna}\mspace{14mu} {port}\mspace{14mu} 7\mspace{70mu} {Antenna}\mspace{14mu} {port}\mspace{14mu} 8}}{{\begin{matrix}\begin{matrix}\begin{matrix}\underset{k}{Subcarrier} \\\underset{k + 1}{Subcarrier}\end{matrix} \\\underset{k + 2}{Subcarrier}\end{matrix} \\\underset{k + 3}{Subcarrier}\end{matrix}\mspace{20mu}\begin{bmatrix}S_{1} & {S_{1}^{{j2\pi}\; k\; {\tau_{1}/N}}} & {S_{1}^{{j2\pi}\; k\; {\tau_{2}/N}}} & {S_{1}^{{j2\pi}\; k\; {\tau_{3}/N}}} & {- S_{2}^{*}} & {{- S_{2}^{*}}^{{j2}\; \pi \; k\; {\tau_{1}/N}}} & {{- S_{2}^{*}}^{{j2}\; \pi \; k\; {\tau_{2}/N}}} & {{- S_{2}^{*}}^{{j2\pi}\; k\; {\tau_{3}/N}}} \\S_{2} & {S_{2}^{{{j2\pi}{({k + 1})}}{\tau_{1}/N}}} & {S_{2}^{{{j2\pi}{({k + 1})}}{\tau_{2}/N}}} & {S_{2}^{{j2\pi}\; {({k + 1})}\; {\tau_{3}/N}}} & S_{1}^{*} & {S_{1}^{*}^{{j2}\; \pi \; {({k + 1})}\; {\tau_{1}/N}}} & {S_{1}^{*}^{{j2}\; \pi \; {({k + 1})}\; {\tau_{2}/N}}} & {S_{1}^{*}^{{{j2\pi}{({k + 1})}}{\tau_{3}/N}}} \\S_{3} & {S_{3}^{{{j2\pi}{({k + 2})}}{\tau_{1}/N}}} & {S_{3}^{{{j2\pi}{({k + 2})}}{\tau_{2}/N}}} & {S_{3}^{{j2\pi}\; {({k + 2})}\; {\tau_{3}/N}}} & {- S_{4}^{*}} & {{- S_{4}^{*}}^{{j2}\; \pi \; {({k + 2})}\; {\tau_{1}/N}}} & {{- S_{4}^{*}}^{{j2}\; \pi \; {({k + 2})}\; {\tau_{2}/N}}} & {{- S_{4}^{*}}^{{{j2\pi}{({k + 2})}}{\tau_{3}/N}}} \\S_{4} & {S_{4}^{{{j2\pi}{({k + 3})}}{\tau_{1}/N}}} & {S_{4}^{{{j2\pi}{({k + 3})}}{\tau_{2}/N}}} & {S_{4}^{{j2\pi}\; {({k + 3})}\; {\tau_{3}/N}}} & S_{3}^{*} & {S_{3}^{*}^{{j2}\; \pi \; {({k + 3})}\; {\tau_{1}/N}}} & {S_{3}^{*}^{{j2}\; \pi \; {({k + 3})}\; {\tau_{2}/N}}} & {S_{3}^{*}^{{{j2\pi}{({k + 3})}}{\tau_{3}/N}}}\end{bmatrix}}\quad} & \;\end{matrix}$ wherein, k represents the k^(th) subcarrier, τ

τ₂

τ₃ are the cyclic delays, kτ/N is the phase rotation, and N is thenumber of points in the inverse Fourier transform.
 9. A space diversitydevice, comprising an orthogonal processing module, a signal cyclicdelay module and a transmitting module, wherein, the orthogonalprocessing module is used to orthogonally process a space frequencyblock coder to acquire transmission signals of part of antenna ports ineight antenna ports; the signal cyclic delay module is used tocyclically delay the acquired transmission signals of antenna ports toacquire the transmission signals of the rest antenna ports; and thetransmitting module is used to make each antenna port transmit theacquired transmission signal in a corresponding time and subcarrier. 10.The space diversity device of claim 9, wherein, said orthogonallyprocessing the space frequency block coder is: multiplying one Alamouticoder pair in the space frequency block coder by a rotation factor sothat the Alamouti coder pair is orthogonal with another Alamouti coderpair when transmitting at the same time.
 11. The space diversity deviceof claim 10, wherein, said rotation factor is e^(jθ), θε[0,2π].
 12. Thespace diversity device of claim 10, wherein, said rotation factor is 1.13. The space diversity device of claim 9, wherein, said orthogonalprocessing module acquires the transmission signals of four or twoantenna ports.
 14. The space diversity method of claim 3, wherein, saidrotation factor is
 1. 15. The space diversity method of claim 14,wherein, said acquiring the transmission signals of part of the antennaports is: acquiring the transmission signals of two antenna ports in theeight antenna ports; and said cyclically delaying the acquiredtransmission signals of the antenna ports is phase rotation processingin frequency domain, said phase rotation processing is: multiplying theacquired transmission signals of the two antenna ports by e^(j2πkτ) ¹^(/N), e^(j2πkτ) ² ^(/N) and e^(j2πkτ) ³ ^(/N) respectively to acquirethe transmission signals of the rest six antenna ports, wherein, N isthe number of points in inverse Fourier transform, k represents a k^(th)subcarrier, and τ₁, τ₂ and τ₃ are cyclic delays in different antennaports.
 16. The space diversity method of claim 15, wherein, acorresponding relationship between the eight antenna ports and a formedspace time coder matrix is: $\begin{matrix}\overset{\mspace{34mu} {{Antenna}\mspace{14mu} {port}\mspace{14mu} 1\mspace{14mu} {Antenna}\mspace{14mu} {port}\mspace{14mu} 2{\mspace{11mu} \mspace{31mu}}{Antenna}\mspace{14mu} {port}\mspace{14mu} 3{\mspace{14mu} \mspace{25mu}}{Antenna}\mspace{14mu} {port}\mspace{14mu} 4\mspace{25mu} {Antenna}\mspace{14mu} {port}\mspace{14mu} 5{\mspace{11mu} \;}{Antenna}\mspace{14mu} {port}\mspace{14mu} 6{\mspace{11mu} \mspace{65mu}}{Antenna}\mspace{14mu} {port}\mspace{14mu} 7{\mspace{11mu} \mspace{70mu}}{Antenna}\mspace{14mu} {port}\mspace{14mu} 8}}{{\begin{matrix}\begin{matrix}\begin{matrix}\underset{k}{Subcarrier} \\\underset{k + 1}{Subcarrier}\end{matrix} \\\underset{k + 2}{Subcarrier}\end{matrix} \\\underset{k + 3}{Subcarrier}\end{matrix}\mspace{20mu}\begin{bmatrix}S_{1} & {S_{1}^{{j2\pi}\; k\; {\tau_{1}/N}}} & {S_{1}^{{j2\pi}\; k\; {\tau_{2}/N}}} & {S_{1}^{{j2\pi}\; k\; {\tau_{3}/N}}} & {- S_{2}^{*}} & {{- S_{2}^{*}}^{{j2}\; \pi \; k\; {\tau_{1}/N}}} & {{- S_{2}^{*}}^{{j2}\; \pi \; k\; {\tau_{2}/N}}} & {{- S_{2}^{*}}^{{j2\pi}\; k\; {\tau_{3}/N}}} \\S_{2} & {S_{2}^{{{j2\pi}{({k + 1})}}{\tau_{1}/N}}} & {S_{2}^{{{j2\pi}{({k + 1})}}{\tau_{2}/N}}} & {S_{2}^{{j2\pi}\; {({k + 1})}\; {\tau_{3}/N}}} & S_{1}^{*} & {S_{1}^{*}^{{j2}\; \pi \; {({k + 1})}\; {\tau_{1}/N}}} & {S_{1}^{*}^{{j2}\; \pi \; {({k + 1})}\; {\tau_{2}/N}}} & {S_{1}^{*}^{{{j2\pi}{({k + 1})}}{\tau_{3}/N}}} \\S_{3} & {S_{3}^{{{j2\pi}{({k + 2})}}{\tau_{1}/N}}} & {S_{3}^{{{j2\pi}{({k + 2})}}{\tau_{2}/N}}} & {S_{3}^{{j2\pi}\; {({k + 2})}\; {\tau_{3}/N}}} & {- S_{4}^{*}} & {{- S_{4}^{*}}^{{j2}\; \pi \; {({k + 2})}\; {\tau_{1}/N}}} & {{- S_{4}^{*}}^{{j2}\; \pi \; {({k + 2})}\; {\tau_{2}/N}}} & {{- S_{4}^{*}}^{{{j2\pi}{({k + 2})}}{\tau_{3}/N}}} \\S_{4} & {S_{4}^{{{j2\pi}{({k + 3})}}{\tau_{1}/N}}} & {S_{4}^{{{j2\pi}{({k + 3})}}{\tau_{2}/N}}} & {S_{4}^{{j2\pi}\; {({k + 3})}\; {\tau_{3}/N}}} & S_{3}^{*} & {S_{3}^{*}^{{j2}\; \pi \; {({k + 3})}\; {\tau_{1}/N}}} & {S_{3}^{*}^{{j2}\; \pi \; {({k + 3})}\; {\tau_{2}/N}}} & {S_{3}^{*}^{{{j2\pi}{({k + 3})}}{\tau_{3}/N}}}\end{bmatrix}}\quad} & \;\end{matrix}$ wherein, k represents the k^(th) subcarrier, τ₁, τ₂ and τ₃are the cyclic delays, kτ/N is the phase rotation, and N is the numberof points in the inverse Fourier transform.
 17. The space diversitydevice of claim 11, wherein, said rotation factor is
 1. 18. The spacediversity device of claim 10, wherein, said orthogonal processing moduleacquires the transmission signals of four or two antenna ports.